The data on gross rent were obtained from answers to long-form questionnaire Items 45a-d, which were asked on a sample basis. Gross rent is the contract rent plus the estimated average monthly cost of utilities (electricity, gas, water and sewer) and fuels (oil, coal, kerosene, wood, etc.) if these are paid by the renter (or paid for the renter by someone else). Gross rent is intended to eliminate differentials that result from varying practices with respect to the inclusion of utilities and fuels as part of the rental payment. The estimated costs of utilities and fuels are reported on an annual basis but are converted to monthly figures for the tabulations. Renter units occupied without payment of cash rent are shown separately as "No cash rent" in the tabulations.

Median gross rent divides the gross rent distribution into two equal parts: one-half of the cases falling below the median gross rent and one-half above the median. Median gross rent is computed on the basis of a standard distribution (see the "Standard Distributions" section under "Derived Measures"). Median gross rent is rounded to the nearest whole dollar. (For more information on medians, see "Derived Measures".)

Aggregate gross rent is calculated by adding together all of the gross rents for occupied housing units in an area. Aggregate gross rent is subject to rounding, which means that all cells in a matrix are rounded to the nearest hundred dollars. (For more information, see "Aggregate" under "Derived Measures".)

Data on gross rent have been collected since 1940 for renter-occupied housing units. In Census 2000, questionnaire Item 45c asked the annual costs for water and sewer in an effort to obtain all costs associated with water usage. In 1990, the question asked the yearly costs for water only.